The present invention is directed to a splittable optical fiber waveguide which is particularly useful as an optical directional coupler and which fiber waveguide has at least one fiber optical waveguide core embedded in a cladding material.
A splittable fiber optical waveguide having a waveguide core embedded in a cladding material is known and an example is disclosed in German O.S. 25 10 114. This waveguide is formed by drawing from a massive initial body and has thermal forces, which were created by an axially unsymmetrical overheating in the forming and softening zone during the drawing process. By means of these forces, a splitting tendency occurs in the fiber along its axis. With a breaking up of the fiber manufactured in this manner, fiber pieces result which have a longitudinal split proceeding from a middle point of the fiber and the splits have different lengths.